org.apache.commons.collections4.map
Class FixedSizeMap<K,V>

java.lang.Object
  extended by org.apache.commons.collections4.map.AbstractIterableMap<K,V>
      extended by org.apache.commons.collections4.map.AbstractMapDecorator<K,V>
          extended by org.apache.commons.collections4.map.FixedSizeMap<K,V>
All Implemented Interfaces:
Serializable, Map<K,V>, BoundedMap<K,V>, Get<K,V>, IterableGet<K,V>, IterableMap<K,V>, Put<K,V>

public class FixedSizeMap<K,V>
extends AbstractMapDecorator<K,V>
implements Map<K,V>, BoundedMap<K,V>, Serializable

Decorates another Map to fix the size, preventing add/remove.

Any action that would change the size of the map is disallowed. The put method is allowed to change the value associated with an existing key however.

If trying to remove or clear the map, an UnsupportedOperationException is thrown. If trying to put a new mapping into the map, an IllegalArgumentException is thrown. This is because the put method can succeed if the mapping's key already exists in the map, so the put method is not always unsupported.

Note that FixedSizeMap is not synchronized and is not thread-safe. If you wish to use this map from multiple threads concurrently, you must use appropriate synchronization. The simplest approach is to wrap this map using Collections.synchronizedMap(Map). This class may throw exceptions when accessed by concurrent threads without synchronization.

This class is Serializable from Commons Collections 3.1.

Since:
3.0
Version:
$Id: FixedSizeMap.java 1479407 2013-05-05 22:07:53Z tn $
See Also:
Serialized Form

Constructor Summary
protected FixedSizeMap(Map<K,V> map)
          Constructor that wraps (not copies).
 
Method Summary
 void clear()
           
 Set<Map.Entry<K,V>> entrySet()
           
static
<K,V> FixedSizeMap<K,V>
fixedSizeMap(Map<K,V> map)
          Factory method to create a fixed size map.
 boolean isFull()
          Returns true if this map is full and no new elements can be added.
 Set<K> keySet()
           
 int maxSize()
          Gets the maximum size of the map (the bound).
 V put(K key, V value)
          Note that the return type is Object, rather than V as in the Map interface.
 void putAll(Map<? extends K,? extends V> mapToCopy)
           
 V remove(Object key)
           
 Collection<V> values()
           
 
Methods inherited from class org.apache.commons.collections4.map.AbstractMapDecorator
containsKey, containsValue, decorated, equals, get, hashCode, isEmpty, size, toString
 
Methods inherited from class org.apache.commons.collections4.map.AbstractIterableMap
mapIterator
 
Methods inherited from class java.lang.Object
clone, finalize, getClass, notify, notifyAll, wait, wait, wait
 
Methods inherited from interface org.apache.commons.collections4.IterableGet
mapIterator
 
Methods inherited from interface org.apache.commons.collections4.Get
containsKey, containsValue, get, isEmpty, size
 

Constructor Detail

FixedSizeMap

protected FixedSizeMap(Map<K,V> map)
Constructor that wraps (not copies).

Parameters:
map - the map to decorate, must not be null
Throws:
IllegalArgumentException - if map is null
Method Detail

fixedSizeMap

public static <K,V> FixedSizeMap<K,V> fixedSizeMap(Map<K,V> map)
Factory method to create a fixed size map.

Type Parameters:
K - the key type
V - the value type
Parameters:
map - the map to decorate, must not be null
Returns:
a new fixed size map
Throws:
IllegalArgumentException - if map is null
Since:
4.0

put

public V put(K key,
             V value)
Description copied from interface: Put
Note that the return type is Object, rather than V as in the Map interface. See the class Javadoc for further info.

Specified by:
put in interface Map<K,V>
Specified by:
put in interface Put<K,V>
Overrides:
put in class AbstractMapDecorator<K,V>
See Also:
Map.put(Object, Object)

putAll

public void putAll(Map<? extends K,? extends V> mapToCopy)
Specified by:
putAll in interface Map<K,V>
Specified by:
putAll in interface Put<K,V>
Overrides:
putAll in class AbstractMapDecorator<K,V>
See Also:
Map.putAll(Map)

clear

public void clear()
Specified by:
clear in interface Map<K,V>
Specified by:
clear in interface Put<K,V>
Overrides:
clear in class AbstractMapDecorator<K,V>
See Also:
Map.clear()

remove

public V remove(Object key)
Specified by:
remove in interface Map<K,V>
Specified by:
remove in interface Get<K,V>
Overrides:
remove in class AbstractMapDecorator<K,V>
See Also:
Map.remove(Object)

entrySet

public Set<Map.Entry<K,V>> entrySet()
Specified by:
entrySet in interface Map<K,V>
Specified by:
entrySet in interface Get<K,V>
Overrides:
entrySet in class AbstractMapDecorator<K,V>
See Also:
Map.entrySet()

keySet

public Set<K> keySet()
Specified by:
keySet in interface Map<K,V>
Specified by:
keySet in interface Get<K,V>
Overrides:
keySet in class AbstractMapDecorator<K,V>
See Also:
Map.keySet()

values

public Collection<V> values()
Specified by:
values in interface Map<K,V>
Specified by:
values in interface Get<K,V>
Overrides:
values in class AbstractMapDecorator<K,V>
See Also:
Map.values()

isFull

public boolean isFull()
Description copied from interface: BoundedMap
Returns true if this map is full and no new elements can be added.

Specified by:
isFull in interface BoundedMap<K,V>
Returns:
true if the map is full

maxSize

public int maxSize()
Description copied from interface: BoundedMap
Gets the maximum size of the map (the bound).

Specified by:
maxSize in interface BoundedMap<K,V>
Returns:
the maximum number of elements the map can hold


Copyright © 2001–2013 The Apache Software Foundation. All rights reserved.